TWIST1 and cancer: These results suggest that: (i) the induction of Twist1 in HT29 cells by platelets involves the contribution of released PGE2 together with other signaling pathways derived from the cross-talk between platelets and cancer cells; (ii) both mechanisms are mitigated by the selective inhibition of platelet function by aspirin and (iii) PGE2 produced by platelet-cancer cell interactions takes part in EMT but not in the formation of a migratory cancer cell.